In today's aircraft many of the structural components used are of fiber composite materials, for example, of carbon fiber composite materials (CFRP). In such materials the electrical conductivity compared with metallic structures is more weakly defined and the quality of an electrical connection based solely on the electrical conductivity of the individual carbon fibers cannot be predicted reliably. For this reason electrical functions, such as, in particular, protection from lightning strike, return paths for currents of electrical loads, provision of a stable electrical earth, and the screening of systems and cable looms from electromagnetic radiation are not undertaken, or are not undertaken to a sufficient extent, by the primary structure.
WO 2009/128991 A1 shows that the lightning protection function can be achieved via a metallic film or a metallic network inlaid into the main panels. Further electrical functions (return paths for currents, stable electrical earth, etc.) are often ensured by a system of additional metallic elements, a so-called electrical structural network (ESN system). The ESN system uses a combination of various metallic structural elements, such as, for example, the metallic seat rails, and profiles arranged in the region of the fuselage structure.
What is disadvantageous in such systems is the fact that the additional metallic components significantly encumber the installation of structures and systems and increase the structural weight. Furthermore the industrial concept, by virtue of the large number of individual parts and the sequence of assembly that must be maintained, is complex in terms of production technology; this has a negative effect on both the production costs, and also on the time required in particular stages of production. Also disadvantageous is the fact that the fiber composite components can be structurally damaged by mechanical effects, for example, by the impact of tools during production. A delamination caused in this manner is difficult to detect visually, but can significantly reduce the mechanical load that can be applied to the component. As a result the component must be dimensioned such that if damage is present that is difficult to detect the end result cannot be failure of the component. Overall such structures are complex in terms of both production and assembly technology, cost intensive, and do not utilize the full potential of the fiber composite mode of construction.